Three-dimensionally printed core box blank

ABSTRACT

A method of manufacturing a cold box core includes injecting unbonded sand into a cold box core tool, the unbonded sand including sand mixed with a resin, the cold box core tool including: a first platen; a first insert half secured to the first platen; a second platen; and a second insert half secured to the second platen and configured to alternately mate with and separate from the first insert half, each of the first insert half and the second insert half being three-dimensionally printed from a polymer material, the first insert half and the second insert half together forming a cavity therebetween defining an outer geometric shape of the cold box core; and injecting gas into the unbonded sand to harden the cold box core.

TECHNICAL FIELD Field of Use

This disclosure relates to cold box core tools and core-making andcasting processes more generally. More specifically, this disclosurerelates to three dimensionally printed cold box core tool insert halves.

Related Art

Casting is a relatively old but still versatile manufacturing processused to manufacture a wide variety of cast parts, the surface geometriesof which can require the use of specially formed “cores.” Tooling usedto produce cores, which are destroyed in the casting process, can bequite expensive due to the time-intensive processes available for theirfabrication.

SUMMARY

It is to be understood that this summary is not an extensive overview ofthe disclosure. This summary is exemplary and not restrictive, and it isintended to neither identify key or critical elements of the disclosurenor delineate the scope thereof. The sole purpose of this summary is toexplain and exemplify certain concepts of the disclosure as anintroduction to the following complete and extensive detaileddescription.

In one aspect, disclosed is a method of manufacturing a cold box core,the method comprising: injecting unbonded sand into a cold box coretool, the unbonded sand comprising sand mixed with a resin, the cold boxcore tool comprising: a first platen; a first insert half secured to thefirst platen; a second platen; and a second insert half secured to thesecond platen and configured to alternately mate with and separate fromthe first insert half, each of the first insert half and the secondinsert half being three-dimensionally printed from a polymer material,the first insert half and the second insert half together forming acavity therebetween defining an outer geometric shape of the cold boxcore; and injecting gas into the unbonded sand to harden the cold boxcore.

In a further aspect, disclosed is a method of manufacturing a cold boxcore tool, the method comprising: printing a first insert half using athree-dimensional printer; and printing a second insert half using thethree-dimensional printer.

Various implementations described in the present disclosure may compriseadditional systems, methods, features, and advantages, which may notnecessarily be expressly disclosed herein but will be apparent to one ofordinary skill in the art upon examination of the following detaileddescription and accompanying drawings. It is intended that all suchsystems, methods, features, and advantages be included within thepresent disclosure and protected by the accompanying claims. Thefeatures and advantages of such implementations may be realized andobtained by means of the systems, methods, features particularly pointedout in the appended claims. These and other features will become morefully apparent from the following description and appended claims, ormay be learned by the practice of such exemplary implementations as setforth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several aspects of the disclosureand together with the description, serve to explain various principlesof the disclosure. The drawings are not necessarily drawn to scale.Corresponding features and components throughout the figures may bedesignated by matching reference characters for the sake of consistencyand clarity.

FIG. 1 is front perspective view of a cold box core tool in an openposition in accordance with one aspect of the current disclosure.

FIG. 2 is a front perspective view of the cold box core tool of FIG. 1showing cold box cores positioned inside the tool.

FIG. 3 is a flowchart describing a method of manufacturing the cold boxcore tool of FIG. 1.

FIG. 4 is a flowchart describing a method of manufacturing a cold boxcore using the cold box core tool of FIG. 1.

DETAILED DESCRIPTION

The present disclosure can be understood more readily by reference tothe following detailed description, examples, drawings, and claims, andtheir previous and following description. However, before the presentdevices, systems, and/or methods are disclosed and described, it is tobe understood that this disclosure is not limited to the specificdevices, systems, and/or methods disclosed unless otherwise specified,as such can, of course, vary. It is also to be understood that theterminology used herein is for the purpose of describing particularaspects only and is not intended to be limiting.

The following description is provided as an enabling teaching of thepresent devices, systems, and/or methods in their best, currently knownaspect. To this end, those skilled in the relevant art will recognizeand appreciate that many changes can be made to the various aspectsdescribed herein, while still obtaining the beneficial results of thepresent disclosure. It will also be apparent that some of the desiredbenefits of the present disclosure can be obtained by selecting some ofthe features of the present disclosure without utilizing other features.Accordingly, those who work in the art will recognize that manymodifications and adaptations to the present disclosure are possible andcan even be desirable in certain circumstances and are a part of thepresent disclosure. Thus, the following description is provided asillustrative of the principles of the present disclosure and not inlimitation thereof.

As used throughout, the singular forms “a,” “an” and “the” includeplural referents unless the context clearly dictates otherwise. Thus,for example, reference to a quantity of one of a particular element cancomprise two or more such elements unless the context indicatesotherwise. In addition, any of the elements described herein can be afirst such element, a second such element, and so forth (e.g., a firstwidget and a second widget, even if only a “widget” is referenced).

Ranges can be expressed herein as from “about” one particular value,and/or to “about” another particular value. When such a range isexpressed, another aspect comprises from the one particular value and/orto the other particular value. Similarly, when values are expressed asapproximations, by use of the antecedent “about” or “substantially,” itwill be understood that the particular value forms another aspect. Itwill be further understood that the endpoints of each of the ranges aresignificant both in relation to the other endpoint, and independently ofthe other endpoint.

For purposes of the current disclosure, a material property or dimensionmeasuring about X or substantially X on a particular measurement scalemeasures within a range between X plus an industry-standard uppertolerance for the specified measurement and X minus an industry-standardlower tolerance for the specified measurement. Because tolerances canvary between different materials, processes and between differentmodels, the tolerance for a particular measurement of a particularcomponent can fall within a range of tolerances.

As used herein, the terms “optional” or “optionally” mean that thesubsequently described event or circumstance may or may not occur, andthat the description comprises instances where said event orcircumstance occurs and instances where it does not.

The word “or” as used herein means any one member of a particular listand also comprises any combination of members of that list. The phrase“at least one of A and B” as used herein means “only A, only B, or bothA and B”; while the phrase “one of A and B” means “A or B.”

To simplify the description of various elements disclosed herein, theconventions of “left,” “right,” “front,” “rear,” “top,” “bottom,”“upper,” “lower,” “inside,” “outside,” “inboard,” “outboard,”“horizontal,” and/or “vertical” may be referenced. Unless statedotherwise, “front” describes that end of the cold box core tool nearestto a loading entrance of the tool; “rear” is that end of the tool thatis opposite or distal the front; “left” is that which is to the left ofor facing left from a person facing towards the front; and “right” isthat which is to the right of or facing right from that same personwhile facing towards the front. “Horizontal” or “horizontal orientation”describes that which is in a plane extending from left to right andaligned with the horizon. “Vertical” or “vertical orientation” describesthat which is in a plane that is angled at 90 degrees to the horizontal.

In one aspect, a cold box core tool and associated methods, systems,devices, and various apparatuses are disclosed herein. In one aspect,the cold box core tool can comprise an insert comprisingthree-dimensionally printed insert portions, which can be insert halves.

Casting is a relatively old but still versatile manufacturing processused to manufacture a wide variety of items—often but not exclusivelyfrom a metal material. For example, casting can be used to manufacturevery strong and durable parts for valves used in a fluid distributionsystem from a material such as, for example and without limitation,ductile iron. Some parts of such valves can have various surfacegeometries. Such surface geometries can define, for example and withoutlimitation, internal cavities and/or undercuts, such as fluid pathsthrough the valves, not able to be cast inside a typical casting toolwithout specially formed “cores.” Such cores, when properly supportedinside the casting tool, can occupy spaces reserved for the cavities ofthe finished cast part. Each core can be made hard enough to maintainits shape during the process of pouring or injecting molten metal intocavities of the casting tool. At a desirable point in the manufacturingprocess—such as after hardening of the molten metal inside the cavitiesof the casting tool—a material forming the core can be flushed from thepart during a “shake-out” process. Typically, the heat from the castpart causes resin to bake out of the previously rigid core until thecore becomes loose sand. The cast part can then optionally be furthercleaned of sand residue and any other residue by a shot-blastingprocess. The core, in essence, can function as a sacrificial element ofthe casting process facilitating cost-effective fabrication of a varietyof geometrically accurate parts.

FIG. 1 shows one aspect of a cold box core tool 100 for manufacturingcold box cores 200 (shown in FIG. 2), which can be sand cores. Shown inan open position and without the manufactured cold box cores 200, thetool 100 can comprise a first platen 110 and a second platen 120. Eachof the platens 110,120 can be or can be incorporated into a pedestal, acarriage, or a truck of a larger machine comprising the cold box coretool 100. The tool 100 can comprise a first insert half 160, which canbe secured to the first platen 110; and a second insert half 170, whichcan be secured to the second platen 120. Each of the first platen 110and the second platen 120 can be a flat plate, which can be formed froma metal such as steel or from any other suitably rigid and strongmaterial.

The first insert half 160 can define an inner surface 161 defining afirst cavity portion 168, and the second insert half 170 can define aninner surface (not shown) defining a second cavity portion (not shown).The first cavity portion 168 and the second cavity portion can togetherform a cavity 108 defining an outer geometric shape of the cold boxcores 200. As shown, the cavity 108 can define a plurality of individualcavities for producing a plurality of cold box cores 200 or core blanksin a single operating cycle of the tool 100. The second insert half 170can be configured to alternately mate with (in a closed position of thetool 100 not shown) and, in the open position shown, separate from thefirst insert half 160. In some aspects, as shown, a separation plane orprimary parting line defined between the first insert half 160 and thesecond insert half 170 of the core box core tool 100 can be oriented ina horizontal plane, in which case the core box core tool 100 can bedescribed as a horizontal core box. In other aspects, the separationplane or primary parting line of the core box core tool 100 can beoriented in a vertical plane, in which case the core box core tool 100can be described as a vertical core box. In some aspects, the separationplane or primary parting line of the core box core tool 100 can beangled with respect to both the horizontal and the vertical planes.

In a typical cold box core tool, the first insert half 160 and thesecond insert half 170 are made using traditional subtractivemanufacturing processes and are typically formed from any one of thefollowing materials: a metal such as steel or cast iron, a wood, or apolymer such as polyurethane—sometimes referred to as “red board”because it is often red in color and is sold in various sizes of boards.These and any other suitable materials can, however, be quite expensiveto obtain, at least in sizes sufficient to produce the tooling inserthalves 160,170. Moreover, a machining time or a “spindle time” duringwhich sections of the tool are being cut and an overall machine time andhuman labor including set-up and breakdown required to produce theinsert halves 160,170 using a subtractive manufacturing process with amachine such as a multi-axis machining center can become a significantportion of the cost of the cold box core tool or the cold box cores 200or both. Significant factors in this cost can include the amount ofmaterial that needs to be removed from such a block or board, thetranslational speed of the tool head being limited by a maximum rate atwhich the tool bits can cut and remove the material, and the specializednature of the tool requiring some level of manual supervision by askilled operator. Availability of only certain board sizes can mean thatsome tools made using traditional processes and materials arenecessarily made from a stack-up of several boards defining jointstherebetween across the insert halves 160,170. In some aspects, it canbe necessary for much of the original block to be machined away to reacheven a near-net shape. In any case, while the cores 200 are a helpfulelement of the casting process, the cores 200 are essentially destroyedby the end of the process and so it can be beneficial to minimize thecost of making them.

Moreover, not only the cost of making a single set of insert halves160,170 but also the longevity of the fabricated insert halves 160,170must be considered to understand the total cost of the tooling. Whileall of the materials traditionally used can be expensive from a laborand material standpoint, the “redboard” or polyurethane toolingtypically can last only about 1,000 “shots” or core production cycles,if that, and dense wood or wood-product tooling typically can last onlyabout 10, 50, or 100 shots. In contrast, the three-dimensionally printedcore box core tool 100 defining a cavity for tensile bar samples hasbeen successfully tested through over 1,000 shots without failure oreven noticeable degradation. This practically means that thethree-dimensionally printed cold box core tool 100 can not only lastlonger than the traditional polyurethane tooling but can over its lifeyield even greater savings based on how many sets of the replacementtool 100 it can effectively replace (in comparison to the replacementtool 100 being manufactured from traditional processes together withtraditionally used materials). It is possible, for example, to saveapproximately 33% or more on a turnkey tool 100 using thethree-dimensionally printed insert halves 160,170 before evenconsidering lifetime savings. While using a metal such as aluminum orsteel for the insert halves 160,170 can result in a tool lasting muchlonger than a tool formed from redboard, the cost of such a tool willgenerally also be even greater.

Even though polyurethane used in redboard tooling is a polymer, asdisclosed herein a polymer used to form the insert halves 160,170 cancomprise carbon fibers defining a carbon-fill percentage ofapproximately 20% or more. In addition, as will be described athree-dimensionally printed insert halves 160,170 can be formed as amonolithic structure without any seams or joints, which as describedabove can be formed during the stack-up of materials using traditionalmanufacturing processes and materials.

In contrast to the typical methods and materials described above, eachof the first insert half 160 and the second insert half 170 can bethree-dimensionally printed. While three-dimensional printing hasgenerally been a viable option for additive manufacturing of small partsfor at least cosmetic design review purposes for well over ten years andthree-dimensional printers are now even available to hobbyists fromso-called “big-box” retailers, three-dimensional printing of largerparts and parts experiencing mechanical loads during use has been anewer development. Three-dimensional printing of tooling is an evennewer development, as tooling such as that used in the manufacture ofthe cold box cores 200 can be subject to compression forces measuringseveral tons, if not 20 tons or more during clamping of the inserthalves 160,170. For example and without limitation, initial tests of thethree-dimensionally printed core box tool 100 were run on a machinerated at 25,000 dekanewtons or just over 56,000 pounds of clampingforce. Even where crush force calculations suggested that athree-dimensionally printed tool could potentially work, suchcalculations also suggested that such a tool may not work and attemptsat the fabrication of three-dimensionally printed tools using previouslydeveloped and known methods to specifically produce a core box core toolthat have been attempted or witnessed by those associated with thecurrent disclosure have resulted in catastrophic failure. In thesefailed attempts, a thermoplastic commonly used by three dimensionalprinters and known as polylactic acid (PLA) was used. Purportedlysuccessful uses of three-dimensionally printed tools have been fordifferent manufacturing processes not involving the same stressesinvolved in cold box core making.

For example, while noting that sandblasting is a process typically usedto remove material from the surface of a part or other structure, theprocess of infusing the sand-resin mixture into the cavity 108 of thetool 100 is in one sense equivalent to sandblasting of the cavity 108 atexemplary pressures of 45-90 pounds per square inch (PSI), which is asimilar pressure to that used during a typical sandblasting process. Yetwear resistance was surprisingly good, i.e. degradation of the tool waswithin acceptable limits even after the aforementioned thousands of coreproduction cycles.

In some aspects, each of the insert halves 160,170 can more specificallybe three dimensionally printed from a polymer material such as, forexample and without limitation, acrylonitrile butadiene styrene (ABS).In other aspects, another polymer material can be used. In some aspects,either or both of the first insert half 160 and the second insert half170 can comprise a carbon fiber in-fill of between 20 percent and 30percent, inclusive, by weight. In some aspects, either or both of thefirst insert half 160 and the second insert half 170 can comprise acarbon fiber in-fill of 20 percent, inclusive, by weight. In someaspects, either or both of the first insert half 160 and the secondinsert half 170 can comprise a carbon fiber in-fill of 25 percent,inclusive, by weight. In some aspects, either or both of the firstinsert half 160 and the second insert half 170 can comprise a carbonfiber in-fill of 30 percent, inclusive, by weight. In some aspects,either or both of the first insert half 160 and the second insert half170 can comprise a carbon fiber in-fill outside of the range of 20percent to 30 percent, inclusive, by weight, if desired based on thecircumstances and desired properties, if experimentation proves thefinal product is acceptable. While not necessarily appreciated in thecurrent context of cold box core making and tool or die makinggenerally, adding fibers to a polymer resin such as ABS before moldinghas in the past generally been found to provide reinforcement andstrength to certain polymers.

Three dimensional printing such as, for example and without limitation,the specific form disclosed herein can be performed on an additivemanufacturing machine such as, for example and without limitation, oneof the LSAM machines produced by Thermwood Corporation of Dale, Ind.,U.S.A. (where “LSAM” is also short for “large scale additivemanufacturing”), or one of the BAAM machines produced by CincinattiIncorporated of Harrison, Ohio, U.S.A. (where “BAAM” is also short for‘big area additive manufacturing”).

Each of the insert halves 160,170 can be secured to the respectiveplatens 110,120 by fasteners (not shown). In some aspects, the inserthalf 170 can be aligned with the insert half 160 during movement of thetool 100 from an open position to the closed position or proximate tothe closed position with geometric features such as, for example andwithout limitation, pins 190 a,b extending from the insert half 160towards the insert half 170. In some aspects, the insert half 170 can bealigned with the insert half 160 during movement of the tool 100 from anopen position to the closed position or proximate to the closed positionby actuators of the system configured to selectively adjust and maintaina position of the insert half 170 with respect to a position of theinsert half 160. A gasket or seal 167 can be positioned inside grooves165 defined in either the insert half 160 or the insert half 170 toprovide a tight seal proximate to and extending around a perimeter ofeach of the cavities 108 for forming the cold box cores 200. The pins190 a,b can be return pins for returning ejector pins 195 to theirpositions during forming of the cores 200, in which case the loweringinsert half 170 upon contact with the pins 190 a,b sufficient to cause adownwards vertical movement of the pins 190 a,b can simultaneously lowerthe ejector pins 195. As shown, the ejector pins 195 are supporting thecores 200 above the cavities 108 for easier removal. As shown, each ofthe pins 190 a,b can be positioned inside bushings 180 a,b installed inthe insert halves 160,170. Each of the ejector pins 195 can likewise bepositioned inside bushings (not shown) installed in the insert halves160,170. Such bushings can facilitate smooth movement of the pins 190a,b, and the ejector pins 195 and reduce wear on the insert halves160,170.

As noted above, only a fraction of the material used to produce theinsert halves 160,170 using the traditional subtractive manufacturingmethods typically remains as part of the finished tool 100 after themachining process is complete, and the time and material used in theprocess is ultimately neither avoidable nor recoverable. In contrast,three dimensional printing of the insert halves 160,170 can be done withonly enough material to produce a “near net” shape. The near net shapecan be made slightly larger in each direction such that light machiningto remove an outermost portion of the tool 100 can bring the tool 100 toits finished shape.

As shown in FIG. 3, a method 300 of manufacturing the cold box core tool100 can comprise one or more of a series of steps 310 a,b through 330.The method 300 can comprise printing each of the first insert half 160and the second insert half 170 using a three-dimensional printer (notshown). As shown in respective steps 310 a,b, printing the first inserthalf 160 can comprise printing a first near-net shape insert half usingthe three-dimensional printer, and printing the second insert half 170can comprise printing a second near-net shape insert half using thethree-dimensional printer. The method 300 can further comprise securingthe first insert half 160 to the first platen 110 of the cold box coretool 100 and securing the second insert half 170 to the second platen120.

As shown in step 320 a, the method can further comprise trimming thefirst near-net shape insert half so that the first near-net shapebecomes the first insert half 160 defining the first cavity portion 168.Similarly, as shown in step 320 b, the method can further comprisetrimming the second near-net shape insert half so that the secondnear-net shape insert half becomes the second insert half 170 definingthe second cavity portion 178. Such trimming can be done with a machinesuch as, for example and without limitation, a CNC router. The firstcavity portion 168 and the second cavity portion 178 can together formthe cavity 108 defining an outer geometric shape of the cold box core200 that the cold box core tool 100 is configured to produce.

Trimming the first insert half 160 can comprise cutting a plurality offirst alignment bushing openings 188, which can upon assembly of thecold box core tool 100 receive the bushings 180 a,b; and trimming thesecond insert half 170 can comprise cutting a plurality of secondalignment bushing openings (not shown). In some aspects, trimming cancomprise the machining or formation during the three dimensionalprinting process of vents extending through the insert halves 160,170 tofacilitate flow of the sand mixture into the cavities 108 during formingof the cores 200. Other features can be formed into the insert halves160,170 as desired just as they might be formed into the insert halves160,170 when formed from the aforementioned traditional subtractivemanufacturing processes.

Between the steps 320 a,b and a step 320, the method can furthercomprise positioning a first alignment bushing in each of the pluralityof first alignment bushing openings of the first insert half 160; andpositioning a second alignment bushing in each of the plurality ofsecond alignment bushing openings of the second insert half 170.

The step 320 can comprise installing the insert halves 160,170(identified in FIG. 3 as inserts 1 and 2) into the surrounding structureof the cold box core tool 100. A machine able to receive the platens110,120 and the insert halves 160,170 can be, for example and withoutlimitation, the L-series “core shooters” available from Laempe Reich ofTrussville, Ala. For example and without limitation, the Laempe Reichmodel LL20 machine or the Laempe Reich model LFB25 can be used.

As shown in FIG. 4, a method 400 of manufacturing the cold box core 200can comprise one or more of a series of steps 410 through 450. Notably,none of the steps of the manufacturing process for the cold box core 200requires heat, hence the “cold” in the name of the tool 100. As shown instep 410, the method 400 can comprise closing the core box core tool100. As shown in step 420, the method 400 can comprise mixing sand withresin to create an unbonded sand mixture. For example and withoutlimitation, the resin can be a phenolic-urethane resin. As shown in step430, the method 400 can comprise injecting the unbonded sand mixtureinto the cold box core tool 100. In some aspects, a pressure of theunbonded sand during its injection into the cold box core tool 100 canmeasure in a range between 45 pounds per square inch (PSI) and 90 PSI orabout 6 bar. In some aspects, the pressure of the unbonded sand duringits injection into the cold box core tool 100 can measure outside of therange between 45 and 90 PSI. In some aspects, the pressure of theunbonded sand during its injection into the cold box core tool 100 canmeasure in a range between 60 and 70 PSI. At pressures within theseranges, as noted above, the injection of the unbonded sand into the coldbox core tool 100 can simulate a harsh sandblasting of the cavity 108 ofthe cold box core tool 100. As shown in step 440, the method 400 canfurther comprise injecting gas into the unbonded sand to harden the coldbox core(s) 200. For example and without limitation, the gas can be anamine gas. In other aspects, another resin and another gas such ascarbon dioxide can be used. As shown in step 450, the method 400 cancomprise opening the cold box core tool 100 and removing the cold boxcore(s) 200. This process can, for example and without limitation, havea cycle time of approximately 45 seconds.

The process of forming the cold box core 200 disclosed herein can beconsidered a form of transfer molding. Transfer molding differs fromcompression molding, another process, in that the mold remains closedduring the molding process. Moreover, the process described hereininvolving the injection of a sand-resin mixture into the cold box coretool 100 can create abrasion forces acting on the insert halves 160,170that are not present in a compression molding process.

One should note that conditional language, such as, among others, “can,”“could,” “might,” or “may,” unless specifically stated otherwise, orotherwise understood within the context as used, is generally intendedto convey that certain aspects include, while other aspects do notinclude, certain features, elements and/or steps. Thus, such conditionallanguage is not generally intended to imply that features, elementsand/or steps are in any way required for one or more particular aspectsor that one or more particular aspects necessarily comprise logic fordeciding, with or without user input or prompting, whether thesefeatures, elements and/or steps are included or are to be performed inany particular aspect.

It should be emphasized that the above-described aspects are merelypossible examples of implementations, merely set forth for a clearunderstanding of the principles of the present disclosure. Any processdescriptions or blocks in flow diagrams should be understood asrepresenting modules, segments, or portions of code which comprise oneor more executable instructions for implementing specific logicalfunctions or steps in the process, and alternate implementations areincluded in which functions may not be included or executed at all, maybe executed out of order from that shown or discussed, includingsubstantially concurrently or in reverse order, depending on thefunctionality involved, as would be understood by those reasonablyskilled in the art of the present disclosure. Many variations andmodifications may be made to the above-described aspect(s) withoutdeparting substantially from the spirit and principles of the presentdisclosure. Further, the scope of the present disclosure is intended tocover any and all combinations and sub-combinations of all elements,features, and aspects discussed above. All such modifications andvariations are intended to be included herein within the scope of thepresent disclosure, and all possible claims to individual aspects orcombinations of elements or steps are intended to be supported by thepresent disclosure.

That which is claimed is:
 1. A method of manufacturing a cold box core,the method comprising: injecting unbonded sand into a cold box coretool, the unbonded sand comprising sand mixed with a resin, the cold boxcore tool comprising: a first platen; a first insert half secured to thefirst platen; a second platen; and a second insert half secured to thesecond platen and configured to alternately mate with and separate fromthe first insert half, each of the first insert half and the secondinsert half being three-dimensionally printed from a polymer material,the first insert half and the second insert half together forming acavity therebetween defining an outer geometric shape of the cold boxcore; and injecting gas into the unbonded sand to harden the cold boxcore.
 2. The method of claim 1, wherein each of the first insert halfand the second insert half is formed from acrylonitrile butadienestyrene (ABS).
 3. The method of claim 2, wherein each of the firstinsert half and the second insert half comprises a carbon fiber in-fillof between 20 percent and 30 percent, inclusive, by weight.
 4. Themethod of claim 1, further comprising three-dimensionally printing eachof the first insert half and the second insert half using a large scaleadditive manufacturing machine.
 5. The method of claim 1, wherein eachof the first insert half and the second insert half defines a monolithicstructure.
 6. The method of claim 1, wherein the resin isphenolic-urethane resin and the gas is amine gas.
 7. The method of claim1, wherein the first insert half defines a first cavity portion at leastin part forming the cavity defining the outer geometric shape of thecold box core.
 8. The method of claim 1, wherein the first insert halfdefines a first cavity portion and the second insert half defines asecond cavity portion, the first cavity portion and the second cavityportion together forming the cavity defining the outer geometric shapeof the cold box core.
 9. A method of manufacturing a cold box core tool,the method comprising: printing a first insert half using athree-dimensional printer; and printing a second insert half using thethree-dimensional printer.
 10. The method of claim 9, furthercomprising: securing the first insert half to a first platen of the coldbox core tool; and securing the second insert half to a second platen ofthe cold box core tool.
 11. The method of claim 9, wherein: printing thefirst insert half comprises printing a first near-net shape insert halfusing the three-dimensional printer; and printing the second insert halfcomprises printing a second near-net shape insert half using thethree-dimensional printer.
 12. The method of claim 11, furthercomprising: trimming the first insert half using a CNC router; andtrimming the second insert half using the CNC router, the first inserthalf and the second insert half together forming a cavity defining anouter geometric shape of a cold box core that the cold box core tool isconfigured to produce.
 13. The method of claim 12, further comprisingtrimming the first insert half using a CNC router so that the firstinsert half defines a first cavity portion at least in part forming thecavity defining the outer geometric shape of the cold box core.
 14. Themethod of claim 12, further comprising: trimming the first insert halfusing a CNC router so that the first insert half defines a first cavityportion; and trimming the second insert half using the CNC router sothat the second insert half defines a second cavity portion, the firstcavity portion and the second cavity portion together forming the cavitydefining the outer geometric shape of the cold box core that the coldbox core tool is configured to produce.
 15. The method of claim 12,wherein: trimming the first insert half comprises cutting a plurality offirst alignment bushing openings; and trimming the second insert halfcomprises cutting a plurality of second alignment bushing openings. 16.The method of claim 15, further comprising positioning a first alignmentbushing in each of the plurality of first alignment bushing openings ofthe first insert half.
 17. The method of claim 16, further comprisingpositioning a second alignment bushing in each of the plurality ofsecond alignment bushing openings of the second insert half.
 18. Themethod of claim 9, wherein: printing the first insert half comprisesforming the first insert half as a monolithic structure; and printingthe second insert half comprises forming the second insert half as amonolithic structure.